This proposal delineates a structured 5-year career development plan that will help the applicant to effectively and efficiently achieve his research career goals. It defines a comprehensive and cohesive program incorporating novel areas of research, participation in formal basic biomedical science courses, and the development of a course in translational research methodologies. The research component Of this program aims to identify the role of the female reproductive hormones relaxin and estrogen in the etiopathogenesis of temporomandibular joint (TMJ) disease in women. Despite their debilitating nature and predilection for women of reproductive age, the etiology and pathogenesis of temporomandibular disorders remain unknown. The applicant's recent findings that relaxin increases the expression of the matrix metalloproteinases (MMPs) collagenase-1 and stromelysin-l in TMJ disc fibrocartilaginous cells, but not in synoviocytes, suggests a potential mechanism of action for this hormone in TMJ diseases. Furthermore, relaxin's induction of these MMPs is potentiated by prior exposure of the cells to beta-estradiol. These observations suggest that disc cells may be specific target sites for the matrixdegradative effects of relaxin. Therefore, the overriding hypothesis proposed studies is that relaxin and estrogen cause TMJ disease in women by increasing the expression of MMPs and decreasing that of their inhibitors and collagen in joint cells. On the basis of recent findings, the specific aims of the R29 grant have been expanded to include studies to (I) identify the promoter sites and transcription factors involved in the induction of collagenase-1 by relaxin, and (2) elucidate the mechanisms by which beta-estradiol potentiates this induction. These studies will provide insights into the molecular regulation of collagenase-l by relaxin and beta-estradiol. Together, the findings of the R29 and proposed studies may be critical in designing specific diagnostic methods and rational treatments for TMJ diseases in women. This research will be complemented by relevant cutting-edge courses in cell, developmental, connective tissue and reproductive biology and in bioinformatics. The short-term goals of this program are to (I) strengthen the applicant's understanding of contemporary molecular and cell biology techniques, (2) enhance the magnitude and depth of his ongoing studies, and (3) generate additional data for an ROl grant application. In the long-term, this period of intensive research-related activity will serve as a springboard for his goal of becoming a competent and successful translational researcher. The Independent Scientist Award will be critical in achieving these goals.